/******************************************************************************
* Project: PROJ.4
* Purpose: Functions for handling individual PJ_GRIDINFO's. Includes
* loaders for all formats but CTABLE (in nad_init.c).
* Author: Frank Warmerdam, warmerdam@pobox.com
*
******************************************************************************
* Copyright (c) 2000, Frank Warmerdam <warmerdam@pobox.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#define PJ_LIB__
#include <projects.h>
#include <string.h>
#include <math.h>
#include <errno.h>
#ifdef _WIN32_WCE
/* assert.h includes all Windows API headers and causes 'LP' name clash.
* Here assert we disable assert() for Windows CE.
* TODO - mloskot: re-implement porting friendly assert
*/
# define assert(exp) ((void)0)
#else
# include <assert.h>
#endif /* _WIN32_WCE */
/************************************************************************/
/* swap_words() */
/* */
/* Convert the byte order of the given word(s) in place. */
/************************************************************************/
static int byte_order_test = 1;
#define IS_LSB (1 == ((unsigned char *) (&byte_order_test))[0])
static void swap_words( unsigned char *data, int word_size, int word_count )
{
int word;
for( word = 0; word < word_count; word++ )
{
int i;
for( i = 0; i < word_size/2; i++ )
{
int t;
t = data[i];
data[i] = data[word_size-i-1];
data[word_size-i-1] = t;
}
data += word_size;
}
}
/************************************************************************/
/* pj_gridinfo_free() */
/************************************************************************/
void pj_gridinfo_free( projCtx ctx, PJ_GRIDINFO *gi )
{
if( gi == NULL )
return;
if( gi->child != NULL )
{
PJ_GRIDINFO *child, *next;
for( child = gi->child; child != NULL; child=next)
{
next=child->next;
pj_gridinfo_free( ctx, child );
}
}
if( gi->ct != NULL )
nad_free( gi->ct );
free( gi->gridname );
if( gi->filename != NULL )
free( gi->filename );
pj_dalloc( gi );
}
/************************************************************************/
/* pj_gridinfo_load() */
/* */
/* This function is intended to implement delayed loading of */
/* the data contents of a grid file. The header and related */
/* stuff are loaded by pj_gridinfo_init(). */
/************************************************************************/
int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
{
struct CTABLE ct_tmp;
if( gi == NULL || gi->ct == NULL )
return 0;
pj_acquire_lock();
if( gi->ct->cvs != NULL )
{
pj_release_lock();
return 1;
}
memcpy(&ct_tmp, gi->ct, sizeof(struct CTABLE));
/* -------------------------------------------------------------------- */
/* Original platform specific CTable format. */
/* -------------------------------------------------------------------- */
if( strcmp(gi->format,"ctable") == 0 )
{
PAFile fid;
int result;
fid = pj_open_lib( ctx, gi->filename, "rb" );
if( fid == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
result = nad_ctable_load( ctx, &ct_tmp, fid );
pj_ctx_fclose( ctx, fid );
gi->ct->cvs = ct_tmp.cvs;
pj_release_lock();
return result;
}
/* -------------------------------------------------------------------- */
/* CTable2 format. */
/* -------------------------------------------------------------------- */
else if( strcmp(gi->format,"ctable2") == 0 )
{
PAFile fid;
int result;
fid = pj_open_lib( ctx, gi->filename, "rb" );
if( fid == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
result = nad_ctable2_load( ctx, &ct_tmp, fid );
pj_ctx_fclose( ctx, fid );
gi->ct->cvs = ct_tmp.cvs;
pj_release_lock();
return result;
}
/* -------------------------------------------------------------------- */
/* NTv1 format. */
/* We process one line at a time. Note that the array storage */
/* direction (e-w) is different in the NTv1 file and what */
/* the CTABLE is supposed to have. The phi/lam are also */
/* reversed, and we have to be aware of byte swapping. */
/* -------------------------------------------------------------------- */
else if( strcmp(gi->format,"ntv1") == 0 )
{
double *row_buf;
int row;
PAFile fid;
fid = pj_open_lib( ctx, gi->filename, "rb" );
if( fid == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
row_buf = (double *) pj_malloc(gi->ct->lim.lam * sizeof(double) * 2);
ct_tmp.cvs = (FLP *) pj_malloc(gi->ct->lim.lam*gi->ct->lim.phi*sizeof(FLP));
if( row_buf == NULL || ct_tmp.cvs == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
for( row = 0; row < gi->ct->lim.phi; row++ )
{
int i;
FLP *cvs;
double *diff_seconds;
if( pj_ctx_fread( ctx, row_buf,
sizeof(double), gi->ct->lim.lam * 2, fid )
!= (size_t)( 2 * gi->ct->lim.lam ) )
{
pj_dalloc( row_buf );
pj_dalloc( ct_tmp.cvs );
pj_ctx_set_errno( ctx, -38 );
return 0;
}
if( IS_LSB )
swap_words( (unsigned char *) row_buf, 8, gi->ct->lim.lam*2 );
/* convert seconds to radians */
diff_seconds = row_buf;
for( i = 0; i < gi->ct->lim.lam; i++ )
{
cvs = ct_tmp.cvs + (row) * gi->ct->lim.lam
+ (gi->ct->lim.lam - i - 1);
cvs->phi = *(diff_seconds++) * ((PI/180.0) / 3600.0);
cvs->lam = *(diff_seconds++) * ((PI/180.0) / 3600.0);
}
}
pj_dalloc( row_buf );
pj_ctx_fclose( ctx, fid );
gi->ct->cvs = ct_tmp.cvs;
pj_release_lock();
return 1;
}
/* -------------------------------------------------------------------- */
/* NTv2 format. */
/* We process one line at a time. Note that the array storage */
/* direction (e-w) is different in the NTv2 file and what */
/* the CTABLE is supposed to have. The phi/lam are also */
/* reversed, and we have to be aware of byte swapping. */
/* -------------------------------------------------------------------- */
else if( strcmp(gi->format,"ntv2") == 0 )
{
float *row_buf;
int row;
PAFile fid;
pj_log( ctx, PJ_LOG_DEBUG_MINOR,
"NTv2 - loading grid %s", gi->ct->id );
fid = pj_open_lib( ctx, gi->filename, "rb" );
if( fid == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
row_buf = (float *) pj_malloc(gi->ct->lim.lam * sizeof(float) * 4);
ct_tmp.cvs = (FLP *) pj_malloc(gi->ct->lim.lam*gi->ct->lim.phi*sizeof(FLP));
if( row_buf == NULL || ct_tmp.cvs == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
for( row = 0; row < gi->ct->lim.phi; row++ )
{
int i;
FLP *cvs;
float *diff_seconds;
if( pj_ctx_fread( ctx, row_buf, sizeof(float),
gi->ct->lim.lam*4, fid )
!= (size_t)( 4 * gi->ct->lim.lam ) )
{
pj_dalloc( row_buf );
pj_dalloc( ct_tmp.cvs );
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
if( !IS_LSB )
swap_words( (unsigned char *) row_buf, 4,
gi->ct->lim.lam*4 );
/* convert seconds to radians */
diff_seconds = row_buf;
for( i = 0; i < gi->ct->lim.lam; i++ )
{
cvs = ct_tmp.cvs + (row) * gi->ct->lim.lam
+ (gi->ct->lim.lam - i - 1);
cvs->phi = *(diff_seconds++) * ((PI/180.0) / 3600.0);
cvs->lam = *(diff_seconds++) * ((PI/180.0) / 3600.0);
diff_seconds += 2; /* skip accuracy values */
}
}
pj_dalloc( row_buf );
pj_ctx_fclose( ctx, fid );
gi->ct->cvs = ct_tmp.cvs;
pj_release_lock();
return 1;
}
/* -------------------------------------------------------------------- */
/* GTX format. */
/* -------------------------------------------------------------------- */
else if( strcmp(gi->format,"gtx") == 0 )
{
int words = gi->ct->lim.lam * gi->ct->lim.phi;
PAFile fid;
fid = pj_open_lib( ctx, gi->filename, "rb" );
if( fid == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
ct_tmp.cvs = (FLP *) pj_malloc(words*sizeof(float));
if( ct_tmp.cvs == NULL )
{
pj_ctx_set_errno( ctx, -38 );
pj_release_lock();
return 0;
}
if( pj_ctx_fread( ctx, ct_tmp.cvs, sizeof(float), words, fid )
!= (size_t)words )
{
pj_dalloc( ct_tmp.cvs );
pj_release_lock();
return 0;
}
if( IS_LSB )
swap_words( (unsigned char *) ct_tmp.cvs, 4, words );
pj_ctx_fclose( ctx, fid );
gi->ct->cvs = ct_tmp.cvs;
pj_release_lock();
return 1;
}
else
{
pj_release_lock();
return 0;
}
}
/************************************************************************/
/* pj_gridinfo_init_ntv2() */
/* */
/* Seek a parent grid file by name from a grid list */
/************************************************************************/
static PJ_GRIDINFO* pj_gridinfo_parent( PJ_GRIDINFO *gilist,
const char *name, int length )
{
while( gilist )
{
if( strncmp(gilist->ct->id,name,length) == 0 ) return gilist;
if( gilist->child )
{
PJ_GRIDINFO *parent=pj_gridinfo_parent( gilist->child, name, length );
if( parent ) return parent;
}
gilist=gilist->next;
}
return gilist;
}
/************************************************************************/
/* pj_gridinfo_init_ntv2() */
/* */
/* Load a ntv2 (.gsb) file. */
/************************************************************************/
static int pj_gridinfo_init_ntv2( projCtx ctx, PAFile fid, PJ_GRIDINFO *gilist )
{
unsigned char header[11*16];
int num_subfiles, subfile;
assert( sizeof(int) == 4 );
assert( sizeof(double) == 8 );
if( sizeof(int) != 4 || sizeof(double) != 8 )
{
pj_log( ctx, PJ_LOG_ERROR,
"basic types of inappropraiate size in pj_gridinfo_init_ntv2()" );
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Read the overview header. */
/* -------------------------------------------------------------------- */
if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
{
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Byte swap interesting fields if needed. */
/* -------------------------------------------------------------------- */
if( !IS_LSB )
{
swap_words( header+8, 4, 1 );
swap_words( header+8+16, 4, 1 );
swap_words( header+8+32, 4, 1 );
swap_words( header+8+7*16, 8, 1 );
swap_words( header+8+8*16, 8, 1 );
swap_words( header+8+9*16, 8, 1 );
swap_words( header+8+10*16, 8, 1 );
}
/* -------------------------------------------------------------------- */
/* Get the subfile count out ... all we really use for now. */
/* -------------------------------------------------------------------- */
memcpy( &num_subfiles, header+8+32, 4 );
/* ==================================================================== */
/* Step through the subfiles, creating a PJ_GRIDINFO for each. */
/* ==================================================================== */
for( subfile = 0; subfile < num_subfiles; subfile++ )
{
struct CTABLE *ct;
LP ur;
int gs_count;
PJ_GRIDINFO *gi;
/* -------------------------------------------------------------------- */
/* Read header. */
/* -------------------------------------------------------------------- */
if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
{
pj_ctx_set_errno( ctx, -38 );
return 0;
}
if( strncmp((const char *) header,"SUB_NAME",8) != 0 )
{
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Byte swap interesting fields if needed. */
/* -------------------------------------------------------------------- */
if( !IS_LSB )
{
swap_words( header+8+16*4, 8, 1 );
swap_words( header+8+16*5, 8, 1 );
swap_words( header+8+16*6, 8, 1 );
swap_words( header+8+16*7, 8, 1 );
swap_words( header+8+16*8, 8, 1 );
swap_words( header+8+16*9, 8, 1 );
swap_words( header+8+16*10, 4, 1 );
}
/* -------------------------------------------------------------------- */
/* Initialize a corresponding "ct" structure. */
/* -------------------------------------------------------------------- */
ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
strncpy( ct->id, (const char *) header + 8, 8 );
ct->id[8] = '\0';
ct->ll.lam = - *((double *) (header+7*16+8)); /* W_LONG */
ct->ll.phi = *((double *) (header+4*16+8)); /* S_LAT */
ur.lam = - *((double *) (header+6*16+8)); /* E_LONG */
ur.phi = *((double *) (header+5*16+8)); /* N_LAT */
ct->del.lam = *((double *) (header+9*16+8));
ct->del.phi = *((double *) (header+8*16+8));
ct->lim.lam = (int) (fabs(ur.lam-ct->ll.lam)/ct->del.lam + 0.5) + 1;
ct->lim.phi = (int) (fabs(ur.phi-ct->ll.phi)/ct->del.phi + 0.5) + 1;
pj_log( ctx, PJ_LOG_DEBUG_MINOR,
"NTv2 %s %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)\n",
ct->id,
ct->lim.lam, ct->lim.phi,
ct->ll.lam/3600.0, ct->ll.phi/3600.0,
ur.lam/3600.0, ur.phi/3600.0 );
ct->ll.lam *= DEG_TO_RAD/3600.0;
ct->ll.phi *= DEG_TO_RAD/3600.0;
ct->del.lam *= DEG_TO_RAD/3600.0;
ct->del.phi *= DEG_TO_RAD/3600.0;
memcpy( &gs_count, header + 8 + 16*10, 4 );
if( gs_count != ct->lim.lam * ct->lim.phi )
{
pj_log( ctx, PJ_LOG_ERROR,
"GS_COUNT(%d) does not match expected cells (%dx%d=%d)\n",
gs_count, ct->lim.lam, ct->lim.phi,
ct->lim.lam * ct->lim.phi );
pj_ctx_set_errno( ctx, -38 );
return 0;
}
ct->cvs = NULL;
/* -------------------------------------------------------------------- */
/* Create a new gridinfo for this if we aren't processing the */
/* 1st subfile, and initialize our grid info. */
/* -------------------------------------------------------------------- */
if( subfile == 0 )
gi = gilist;
else
{
gi = (PJ_GRIDINFO *) pj_malloc(sizeof(PJ_GRIDINFO));
memset( gi, 0, sizeof(PJ_GRIDINFO) );
gi->gridname = strdup( gilist->gridname );
gi->filename = strdup( gilist->filename );
gi->next = NULL;
}
gi->ct = ct;
gi->format = "ntv2";
gi->grid_offset = pj_ctx_ftell( ctx, fid );
/* -------------------------------------------------------------------- */
/* Attach to the correct list or sublist. */
/* -------------------------------------------------------------------- */
if( strncmp((const char *)header+24,"NONE",4) == 0 )
{
if( gi != gilist )
{
PJ_GRIDINFO *lnk;
for( lnk = gilist; lnk->next != NULL; lnk = lnk->next ) {}
lnk->next = gi;
}
}
else
{
PJ_GRIDINFO *lnk;
PJ_GRIDINFO *gp = pj_gridinfo_parent(gilist,
(const char*)header+24,8);
if( gp == NULL )
{
pj_log( ctx, PJ_LOG_ERROR,
"pj_gridinfo_init_ntv2(): "
"failed to find parent %8.8s for %s.\n",
(const char *) header+24, gi->ct->id );
for( lnk = gilist; lnk->next != NULL; lnk = lnk->next ) {}
lnk->next = gi;
}
else
{
if( gp->child == NULL )
{
gp->child = gi;
}
else
{
for( lnk = gp->child; lnk->next != NULL; lnk = lnk->next ) {}
lnk->next = gi;
}
}
}
/* -------------------------------------------------------------------- */
/* Seek past the data. */
/* -------------------------------------------------------------------- */
pj_ctx_fseek( ctx, fid, gs_count * 16, SEEK_CUR );
}
return 1;
}
/************************************************************************/
/* pj_gridinfo_init_ntv1() */
/* */
/* Load an NTv1 style Canadian grid shift file. */
/************************************************************************/
static int pj_gridinfo_init_ntv1( projCtx ctx, PAFile fid, PJ_GRIDINFO *gi )
{
unsigned char header[176];
struct CTABLE *ct;
LP ur;
assert( sizeof(int) == 4 );
assert( sizeof(double) == 8 );
if( sizeof(int) != 4 || sizeof(double) != 8 )
{
pj_log( ctx, PJ_LOG_ERROR,
"basic types of inappropraiate size in nad_load_ntv1()" );
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Read the header. */
/* -------------------------------------------------------------------- */
if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
{
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Regularize fields of interest. */
/* -------------------------------------------------------------------- */
if( IS_LSB )
{
swap_words( header+8, 4, 1 );
swap_words( header+24, 8, 1 );
swap_words( header+40, 8, 1 );
swap_words( header+56, 8, 1 );
swap_words( header+72, 8, 1 );
swap_words( header+88, 8, 1 );
swap_words( header+104, 8, 1 );
}
if( *((int *) (header+8)) != 12 )
{
pj_log( ctx, PJ_LOG_ERROR,
"NTv1 grid shift file has wrong record count, corrupt?" );
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Fill in CTABLE structure. */
/* -------------------------------------------------------------------- */
ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
strcpy( ct->id, "NTv1 Grid Shift File" );
ct->ll.lam = - *((double *) (header+72));
ct->ll.phi = *((double *) (header+24));
ur.lam = - *((double *) (header+56));
ur.phi = *((double *) (header+40));
ct->del.lam = *((double *) (header+104));
ct->del.phi = *((double *) (header+88));
ct->lim.lam = (int) (fabs(ur.lam-ct->ll.lam)/ct->del.lam + 0.5) + 1;
ct->lim.phi = (int) (fabs(ur.phi-ct->ll.phi)/ct->del.phi + 0.5) + 1;
pj_log( ctx, PJ_LOG_DEBUG_MINOR,
"NTv1 %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
ct->lim.lam, ct->lim.phi,
ct->ll.lam, ct->ll.phi, ur.lam, ur.phi );
ct->ll.lam *= DEG_TO_RAD;
ct->ll.phi *= DEG_TO_RAD;
ct->del.lam *= DEG_TO_RAD;
ct->del.phi *= DEG_TO_RAD;
ct->cvs = NULL;
gi->ct = ct;
gi->grid_offset = pj_ctx_ftell( ctx, fid );
gi->format = "ntv1";
return 1;
}
/************************************************************************/
/* pj_gridinfo_init_gtx() */
/* */
/* Load a NOAA .gtx vertical datum shift file. */
/************************************************************************/
static int pj_gridinfo_init_gtx( projCtx ctx, PAFile fid, PJ_GRIDINFO *gi )
{
unsigned char header[40];
struct CTABLE *ct;
double xorigin,yorigin,xstep,ystep;
int rows, columns;
assert( sizeof(int) == 4 );
assert( sizeof(double) == 8 );
if( sizeof(int) != 4 || sizeof(double) != 8 )
{
pj_log( ctx, PJ_LOG_ERROR,
"basic types of inappropraiate size in nad_load_gtx()" );
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Read the header. */
/* -------------------------------------------------------------------- */
if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
{
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Regularize fields of interest and extract. */
/* -------------------------------------------------------------------- */
if( IS_LSB )
{
swap_words( header+0, 8, 4 );
swap_words( header+32, 4, 2 );
}
memcpy( &yorigin, header+0, 8 );
memcpy( &xorigin, header+8, 8 );
memcpy( &ystep, header+16, 8 );
memcpy( &xstep, header+24, 8 );
memcpy( &rows, header+32, 4 );
memcpy( &columns, header+36, 4 );
if( xorigin < -360 || xorigin > 360
|| yorigin < -90 || yorigin > 90 )
{
pj_log( ctx, PJ_LOG_ERROR,
"gtx file header has invalid extents, corrupt?");
pj_ctx_set_errno( ctx, -38 );
return 0;
}
/* -------------------------------------------------------------------- */
/* Fill in CTABLE structure. */
/* -------------------------------------------------------------------- */
ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
strcpy( ct->id, "GTX Vertical Grid Shift File" );
ct->ll.lam = xorigin;
ct->ll.phi = yorigin;
ct->del.lam = xstep;
ct->del.phi = ystep;
ct->lim.lam = columns;
ct->lim.phi = rows;
/* some GTX files come in 0-360 and we shift them back into the
expected -180 to 180 range if possible. This does not solve
problems with grids spanning the dateline. */
if( ct->ll.lam >= 180.0 )
ct->ll.lam -= 360.0;
if( ct->ll.lam >= 0.0 && ct->ll.lam + ct->del.lam * ct->lim.lam > 180.0 )
{
pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
"This GTX spans the dateline! This will cause problems." );
}
pj_log( ctx, PJ_LOG_DEBUG_MINOR,
"GTX %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
ct->lim.lam, ct->lim.phi,
ct->ll.lam, ct->ll.phi,
ct->ll.lam + (columns-1)*xstep, ct->ll.phi + (rows-1)*ystep);
ct->ll.lam *= DEG_TO_RAD;
ct->ll.phi *= DEG_TO_RAD;
ct->del.lam *= DEG_TO_RAD;
ct->del.phi *= DEG_TO_RAD;
ct->cvs = NULL;
gi->ct = ct;
gi->grid_offset = 40;
gi->format = "gtx";
return 1;
}
/************************************************************************/
/* pj_gridinfo_init() */
/* */
/* Open and parse header details from a datum gridshift file */
/* returning a list of PJ_GRIDINFOs for the grids in that */
/* file. This superceeds use of nad_init() for modern */
/* applications. */
/************************************************************************/
PJ_GRIDINFO *pj_gridinfo_init( projCtx ctx, const char *gridname )
{
char fname[MAX_PATH_FILENAME+1];
PJ_GRIDINFO *gilist;
PAFile fp;
char header[160];
errno = pj_errno = 0;
ctx->last_errno = 0;
/* -------------------------------------------------------------------- */
/* Initialize a GRIDINFO with stub info we would use if it */
/* cannot be loaded. */
/* -------------------------------------------------------------------- */
gilist = (PJ_GRIDINFO *) pj_malloc(sizeof(PJ_GRIDINFO));
memset( gilist, 0, sizeof(PJ_GRIDINFO) );
gilist->gridname = strdup( gridname );
gilist->filename = NULL;
gilist->format = "missing";
gilist->grid_offset = 0;
gilist->ct = NULL;
gilist->next = NULL;
/* -------------------------------------------------------------------- */
/* Open the file using the usual search rules. */
/* -------------------------------------------------------------------- */
strcpy(fname, gridname);
if (!(fp = pj_open_lib(ctx, fname, "rb"))) {
ctx->last_errno = 0; /* don't treat as a persistent error */
return gilist;
}
gilist->filename = strdup(fname);
/* -------------------------------------------------------------------- */
/* Load a header, to determine the file type. */
/* -------------------------------------------------------------------- */
if( pj_ctx_fread( ctx, header, sizeof(header), 1, fp ) != 1 )
{
pj_ctx_fclose( ctx, fp );
pj_ctx_set_errno( ctx, -38 );
return gilist;
}
pj_ctx_fseek( ctx, fp, SEEK_SET, 0 );
/* -------------------------------------------------------------------- */
/* Determine file type. */
/* -------------------------------------------------------------------- */
if( strncmp(header + 0, "HEADER", 6) == 0
&& strncmp(header + 96, "W GRID", 6) == 0
&& strncmp(header + 144, "TO NAD83 ", 16) == 0 )
{
pj_gridinfo_init_ntv1( ctx, fp, gilist );
}
else if( strncmp(header + 0, "NUM_OREC", 8) == 0
&& strncmp(header + 48, "GS_TYPE", 7) == 0 )
{
pj_gridinfo_init_ntv2( ctx, fp, gilist );
}
else if( strlen(gridname) > 4
&& (strcmp(gridname+strlen(gridname)-3,"gtx") == 0
|| strcmp(gridname+strlen(gridname)-3,"GTX") == 0) )
{
pj_gridinfo_init_gtx( ctx, fp, gilist );
}
else if( strncmp(header + 0,"CTABLE V2",9) == 0 )
{
struct CTABLE *ct = nad_ctable2_init( ctx, fp );
gilist->format = "ctable2";
gilist->ct = ct;
pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
"Ctable2 %s %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)\n",
ct->id,
ct->lim.lam, ct->lim.phi,
ct->ll.lam * RAD_TO_DEG, ct->ll.phi * RAD_TO_DEG,
(ct->ll.lam + (ct->lim.lam-1)*ct->del.lam) * RAD_TO_DEG,
(ct->ll.phi + (ct->lim.phi-1)*ct->del.phi) * RAD_TO_DEG );
}
else
{
struct CTABLE *ct = nad_ctable_init( ctx, fp );
if (ct == NULL)
{
pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
"CTABLE ct is NULL.");
} else
{
gilist->format = "ctable";
gilist->ct = ct;
pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
"Ctable %s %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)\n",
ct->id,
ct->lim.lam, ct->lim.phi,
ct->ll.lam * RAD_TO_DEG, ct->ll.phi * RAD_TO_DEG,
(ct->ll.lam + (ct->lim.lam-1)*ct->del.lam) * RAD_TO_DEG,
(ct->ll.phi + (ct->lim.phi-1)*ct->del.phi) * RAD_TO_DEG );
}
}
pj_ctx_fclose(ctx, fp);
return gilist;
}